Genus

Leptosphaeria

Species

australiensis

Author

(Cribb & J.W. Cribb) G.C. Hughes, Syesis 2: 132 (1969)

Class

Dothideomycetes, Subclass Pleosporomycetidae

Order

Pleosporales

Family

Leptosphaeriaceae

Synonymy: ≡ Metasphaeria australiensis Cribb & J.W. Cribb, 3: 79 (1955)

Description

Sexual morph: Ascomata 100-200 μm high, 120-195 μm diam., obpyriform, immersed, ostiolate, papillate, coriaceous, fuscous or light brown, lighter colored at the base, solitary or gregarious. Necks 70-225 μm long, 30-50 μm diam. at the tip, 70-75 μm at the base, conical or subcylindrical, fuscous or almost hyaline, ostioles line with periphyses, 1.5-2.2 μm diam. Peridium 10-25 μm thick, two layer, outer layer composed of small, irregularly rounded, thick-walled, pigmented cells, forming a textura angularis, inner layer composed of thin-walled, light-coloured, elongated cells. Pseudoparaphyses 1-2.2 μm diam., septate, somewhat branched, with gelatinous walls, persistent. Asci 70-105 × 10-15 μm, 8-spored, clavate-fusiform, pedunculate, indistinctly bitunicate, thick-walled when young, later relatively thin-walled, with apical apparatus, developing at the base of the ascoma venter. Ascospores 19-27 × 5.5-9 μm, biseriate, ellipsoidal, fusiform or clavate-fusiform, three-septate, constricted at the septa, hyaline. Asexual morph: Undetermined. (Description based on Pang et al. (2011)).

Key references:

Alias SA, Jones EBG. (2000) Colonization of mangrove wood by marine fungi at Kuala Selangor mangrove stand. In: Aquatic Mycology across the Millennium (Hyde KD, Ho WH, Pointing SB, eds.), Fungal Diversity Press, Hong Kong. pp. 9-21.

Alias SA, Jones EBG. (2009) Marine fungi from mangroves of Malaysia. Institute Ocean and Earth Sciences, University of Malaya, Kuala Lumpur. p. 108

Hyde KD, Jones EBG, Ariyawansha H, Liu JK, Binder M, Jayawardene N, Boehm E, Boonmee S et al. (2013) Families of Dothideomycetes. Fungal Diversity 63: 1-313.

Jones EBG, Suetrong S, Sakayaroj J, Bahkali AH, Abdel-Wahab MA, Boekhout T, Pang KL (2015) Classification of marine Ascomycota, Basidiomycota, Blastocladiomycota and Chytridiomycota. Fungal Diversity 73: 1-72.

Khashnobish A, Shearer CA. (1996a) Re-examination of some Leptosphaeria and Phaeosphaeria species, Passeriniella obiones and Melanomma radicans. Mycological Research 100: 1341-54.

Khashnobish A, Shearer CA. (1996b) Phylogenetic relationships in some Leptosphaeria and Phaeosphaeria species. Mycological Research 100: 1355-1363.

Kohlmeyer J, Kohlmeyer E (1979) Marine mycology, The higher fungi. Academic press, New York.

Pang KL, Jheng JS, Jones EBG (2011) Marine mangrove fungi of Taiwan. National Taiwan Ocean Univ., Chilung, pp. 1-131

Shoemaker RA, Babcock CE. (1989) Phaeosphaeria. Canadian Journal of Botany 67: 1500-1599.

Key to the marine Leptosphaeria species:

Ascospores with a wide sheath 2

Ascospores with an indistinct sheath or lacking a sheath 3

Ascospores 18-25 x 6-8 μm, on mangrove wood, tropical L. avicenniae

Ascospores 28-44 x 8-12 μm, on wood and Spartina culms, temperate L. pelagica

Ascospores with 3 septa 4

Ascospores with 3-5 septa, 30-37.5 x 7.5-11.5 μm, Indistinct sheath, on the palm Nypa L. nypicola

Ascospores 12-16 x 4-5.5 μm, olive brown, on Salicornia, on wood L. peruviana

Ascospores 19-27 x 6-9 μm, on mangrove wood L. australiensis

Ascospores 35-68 x 8-12 μm, on Spartina, Juncus culms, on wood L. marina

Image: Leptosphaeria australiensis. (a) Section of immersed ascoma. (b) Neck with
periphyses. (c) Two-layered peridium, outer layer of cells of textura angularis, inner layer of
elongated cells. (d) Cylindrical bitunicate asci with an apical apparatus and pseudoparaphyses.
(e) Hyaline, bicelled ascospore with large oil globules. Scale bar: a=50 μm; b, d=30 μm; c, e=10. Photo reproduced with the permission of the National Taiwan Ocean University.
μm.

Type & Location:

Other Specimens:

Substratum:

saprobic on dead mangrove wood.

Habitat:

Distribution:

Aldabra, Andaman Islands, Australia, Bahamas, Belize, Bermuda, Brazil, Brunei, Columbia, Fiji, Galapagos, Hong Kong, India, Indonesia, Liberia, Malaysia, Maldives, Martinique, Mauritius, Mexico, Nicobar Islands, Philippines, Republic of Trinidad and Tobago, Seychelles, Sierra Leone, Society Islands, South Africa, Taiwan, Thailand, USA, Venezuela

Pertinent Literature:

Comments:

NOTES: This is another core mangrove species (Alias & Jones 2000, 2009, Pang et al. 2011), particularly on Rhizophora wood, and often an early colonizer of submerged wood. Eight marine Leptosphaeria species are known from marine habitats including those on mangrove wood (L. australiensis, L. avicenniae, L. peruviana c.f.), Spartina culms (L. pelagica) and the brackish water palm Nypa fruticans (L. nypicola) (Jones et al. 2015). These species have not been studied at the molecular level to determine if they are monophyletic. Kohlmeyer and Kohlmeyer list 13 Leptosphaeria species, but many have been transferred to other genera, e.g. Leptosphaeria orae-maris has been transferred to Phaeosphaeria based on molecular studies and morphological observations (Shoemaker & Babcock 1989, Khashnobish & Shearer 1996a, b). There is therefore a need to collect, isolate and sequence the marine Leptosphaeria species to resolve their taxonomic affiliations (Hyde et al. 2013, Jones et al. 2015).

Images

Fig 1